I have a discrepancy on my numbers too. You can correct it two ways, the laborious way is by alphabetising the list, and then doing the same thing to your friends list in the flash box on the left, comparing the two, then adding in the missing friends manually.
Or you can do it the technical way by looking into your browsers developer tools, finding an xml file, copying it into a code editor, then finish off by throwing a regular expression at it, that will give you a complete list.
If anyone is interested as to how you get names from a list of pictures, here's how that works.
An image, like everything else on a web page is an element, and an element can have attributes. One of the attributes that an image can have is an 'alt' attribute, this stands for alternative and has a text value. It is this text value that is displayed if the image cannot be loaded for any reason, and it is also read out by screen readers for partially sighted or blind users, as obviously screen readers are not clever enough to describe images, so if you create websites you should always use the alt attribute for a brief description of any images. Anyway, it is this text value that gets picked up when we copy our friends pictures and paste into Notepad.